Imprint apparatus that forms a pattern of an imprint material on a substrate-side pattern region of a substrate using a mold, and related methods

ABSTRACT

An imprint apparatus that forms a pattern of an imprint material on a substrate-side pattern region of a substrate by using a mold. A heating unit heats a partial region of the substrate, the partial region corresponding to the substrate-side pattern region, by irradiating the substrate with light that has passed through the mold and has a first wavelength different from light having a second wavelength for curing the imprint material. The heating unit heats the partial region to deform the substrate-side pattern region by forming an uneven temperature distribution on the substrate-side pattern region by an irradiation of the light having the first wavelength with an uneven illumination distribution.

CLAIM OF PRIORITY

This application is a continuation application of copending U.S. patentapplication Ser. No. 13/649,448, filed Oct. 12, 2012, which is herebyincorporated by reference in its entirety.

This application also claims the benefit of Japanese Patent ApplicationNo. 2011-226637, filed Oct. 14, 2011, and Japanese Patent ApplicationNo. 2012-202990, filed on Sep. 14, 2012, which are hereby incorporatedby reference herein in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an imprint apparatus that forms apattern of an imprint material on a substrate-side pattern region of asubstrate using a mold, a related imprint method, and an articlemanufacturing method using imprint the method.

Description of the Related Art

As the demand for microfabrication of semiconductor devices or MEMSincreases, not only has conventional photolithography technology, butalso, microfabrication technology, in which an uncured resin on asubstrate is molded by a mold to thereby form a resin pattern on thesubstrate, been receiving attention. This technology is also referred toas an “imprint technology”, by which a fine structure with dimensions ofa few nanometers can be formed on a substrate. One example of imprinttechnologies includes a photo-curing method. An imprint apparatusemploying the photo-curing method first applies an ultraviolet curableresin (imprint material, photocurable resin) to a shot region (imprintregion) on a substrate (wafer). Next, the resin (uncured resin) ismolded by a mold. After the ultraviolet curable resin is irradiated withultraviolet light for curing, the cured resin is released from the mold,whereby a resin pattern is formed on the substrate.

Here, in a series of device manufacturing steps, heat processing in afilm formation step, such as sputtering, is performed on a substrate tobe subjected to imprint processing. Consequently, the entire substratemay be expanded or reduced, resulting in a change in the shape (or size)of the pattern region in the direction of two orthogonal in-plane axes.Thus, in an imprint apparatus, the shape of the pattern region(substrate-side pattern region) pre-formed on a substrate needs to bematched with the shape of the pattern region formed on a mold when themold is pressed against the resin on the substrate. As a technique formaking the shape of a substrate-side pattern region, which is slightlydeformed, match the shape of the pattern region formed on a mold,Japanese Patent Laid-Open No. 2008-504141 discloses an apparatus thatdeforms a mold (pattern region) by imparting an external force to theouter periphery of the mold. In the apparatus disclosed in JapanesePatent Laid-Open No. 2008-504141, however, if the material used for themold is quartz, the mold has a Poisson's ratio of 0.16 and, thus, if oneend of the mold is pressed in the axial direction of the mold, the otherend of the mold is expanded in a direction orthogonal to the axis. Thus,if such deformation occurs according to the Poisson's ratio of the mold,the plane of the mold is not easily deformed linearly, when it isdesired that the mold is particularly deformed into a trapezoidal shape,resulting in adverse effects on superposition accuracy. Accordingly, asa method for preventing the mold from being deformed depending on thePoisson's ratio thereof upon such shape correction, WO 2009/153925discloses an imprint method that makes the shape of a substrate-sidepattern region match the shape of the pattern region formed on a mold byheat-deforming the mold.

If the material used for the mold is quartz, however, the thermalexpansion coefficient of quartz is 0.51 ppm, whereas the thermalexpansion coefficient of silicon, which is the material used for thesubstrate, is 2.4 ppm. The thermal expansion coefficients of the moldand the substrate differ by an order of magnitude. Thus, in the methoddisclosed in WO 2009/153925, the heat is transferred from the moldsubjected to thermal deformation to the substrate, from the instant thatthe mold is pressed against the pattern formed on the substrate. Sincethe surface of the substrate having a relatively large thermal expansioncoefficient may be largely deformed due to the heat, it is difficult tosuppress adverse effects on superposition accuracy.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made in view of theforegoing circumstance and provides an imprint apparatus, an imprintmethod, and device manufacturing methods that are advantageous forsuperposition of a pre-existing pattern region formed on a substrate anda resin pattern region to be newly formed during imprint processing.

According to one aspect, the present invention provides an imprintapparatus that forms a pattern of an imprint material on asubstrate-side pattern region of a substrate by using a mold. Theimprint apparatus includes a heating unit configured to heat a partialregion of the substrate, the partial region corresponding to thesubstrate-side pattern region, by irradiating the substrate with lightthat has passed through the mold and has a first wavelength differentfrom light having a second wavelength for curing the imprint material.The heating unit is configured to heat the partial region to deform thesubstrate-side pattern region by forming an uneven temperaturedistribution on the substrate-side pattern region by irradiation of thelight having the first wavelength with an uneven illuminationdistribution.

According to another aspect, the present invention provides an imprintmethod for forming a pattern of an imprint material on a substrate-sidepattern region of a substrate by using a mold. The method includesdeforming a partial region of the substrate, the partial regioncorresponding to the substrate-side pattern region, by irradiating thesubstrate with light that has passed through the mold and has a firstwavelength different from light having a second wavelength for curingthe imprint material, and curing the imprint material by irradiating thelight having the second wavelength in a state in which thesubstrate-side pattern region is deformed and the mold is contacted withthe imprint material. The step of deforming includes forming an uneventemperature distribution on the substrate-side pattern region byirradiation of the light having the first wavelength with an unevenillumination distribution.

According to a further aspect, the present invention provides a devicemanufacturing method for manufacturing a device. The method includesforming a pattern of an imprint material on a substrate-side patternregion of a substrate by using a mold under an imprint method, andprocessing the substrate on which an imprint material pattern has beenformed to manufacture the device. The imprint method includes deforminga partial region of the substrate, the partial region corresponding tothe substrate-side pattern region, by irradiating the substrate withlight that has passed through the mold and has a first wavelengthdifferent from light having a second wavelength for curing the imprintmaterial, and curing the imprint material by irradiating the lighthaving the second wavelength in a state in which the substrate-sidepattern region is deformed and the mold is contacted with the imprintmaterial. The step of deforming includes forming an uneven temperaturedistribution on the substrate-side pattern region by irradiation of thelight having the first wavelength with an uneven illuminationdistribution.

In still another aspect, the present invention provides an imprintmethod for forming a pattern of an imprint material on a substrate-sidepattern region of a substrate by using a mold. The method includes stepsof obtaining shape difference information between a mold-side patternregion of the mold and the substrate-side pattern region, deforming themold-side pattern region by applying a force to the mold and thesubstrate-side pattern region by irradiating a partial region of thesubstrate, the partial region corresponding to the substrate-sidepattern region, with light that has passed through the mold and has afirst wavelength, and curing the imprint material in a state in whichthe imprint material on the deformed substrate-side pattern region isbrought into contact with the mold by irradiating light having a secondwavelength different from the first wavelength. In the step ofdeforming, the force and an illuminance distribution of the light arecontrolled based on the obtained shape difference.

In yet another aspect, the present invention provides a devicemanufacturing method for manufacturing a device. The method includesforming a pattern of an imprint material on a substrate-side patternregion of a substrate by using a mold under an imprint method, andprocessing the substrate on which an imprint material pattern has beenformed to manufacture the device. The imprint method includes steps ofobtaining shape difference information between a mold-side patternregion of the mold and the substrate-side pattern region, deforming themold-side pattern region by applying a force to the mold and thesubstrate-side pattern region by irradiating a partial region of thesubstrate, the partial region corresponding to the substrate-sidepattern region, with light that has passed through the mold and has afirst wavelength, and curing the imprint material in a state in whichthe imprint material on the deformed substrate-side pattern region isbrought into contact with the mold by irradiating light having a secondwavelength different from the first wavelength. In the step ofdeforming, the force and an illuminance distribution of the light arecontrolled based on the obtained shape difference.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the configuration of an imprintapparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the configuration and arrangement of awafer heating mechanism according to the first embodiment.

FIG. 3 is a flowchart illustrating the flow of shape correction of apre-existing pattern region.

FIG. 4 is a diagram illustrating an irradiation dose distribution, orthe like, with respect to a pre-existing pattern region.

FIG. 5 is a diagram illustrating another irradiation dose distribution,or the like, with respect to a pre-existing pattern region.

FIG. 6 is a graph plotting displacement amount with respect to heatingtime for a pre-existing pattern region.

FIG. 7 is a flowchart illustrating the flow of mold shape correction.

FIGS. 8A to 8C are graphs plotting irradiation dose with respect toheating time according to a second embodiment.

FIG. 9 is a diagram illustrating the configuration and arrangement of awafer heating mechanism according to another embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereafter, preferred embodiments of the present invention will now bedescribed with reference to the accompanying drawings.

First Embodiment

First, a description will be given of the configuration of an imprintapparatus according to a first embodiment of the present invention. FIG.1 is a diagram illustrating the configuration of an imprint apparatus 1of the present embodiment. The imprint apparatus 1 is an apparatus thatmolds an uncured resin on a wafer (on a substrate), i.e., a substrate tobe treated, using a mold, to thereby form a resin pattern on the wafer,which is used in the manufacture of devices such as semiconductordevices, and the like, as articles. Note that the imprint apparatus ofthe present embodiment is an apparatus employing a photo-curing method.In the following drawings, a description will be given where the Z axisis aligned parallel to the optical axis of an irradiation system thatirradiates a resin on a wafer with ultraviolet rays (ultraviolet light),and mutually orthogonal X and Y axes are aligned in a planeperpendicular to the Z axis. First, the imprint apparatus 1 includes alight irradiation unit 2, a mold holding mechanism 3, a wafer stage 4,an application unit 5, a wafer heating mechanism 6, and a control unit7.

The light irradiation unit 2 irradiates a mold 8 with ultraviolet light9 during imprint processing. The light irradiation unit 2 is constitutedby a light source (not shown) and an optical element (not shown) thatadjusts the ultraviolet light 9 emitted from the light source to lightsuitable for imprint.

The outer peripheral shape of the mold 8 is square and the mold 8includes a pattern region (e.g., the concave and convex pattern of acircuit pattern, or the like, to be transferred) 8 a, which isthree-dimensionally formed on the surface facing a wafer 10. Also, thematerial of the mold 8 is a material through which the ultraviolet light9 can pass and, as an example in the present embodiment, is quartz.Furthermore, for ease of deformation, as described below, the mold 8 maybe of a shape in which a cavity (concave portion) of a circular planershape having a certain depth is formed on the surface on which theultraviolet light 9 is irradiated.

The mold holding mechanism 3 has a mold chuck 11 that holds the mold 8and a mold drive mechanism 12 that holds the mold chuck 11, and movesthe mold 8 (the mold chuck 11). The mold chuck 11 may hold the mold 8 bysuctioning or attracting the outer peripheral region of the surface ofthe mold 8 irradiated with the ultraviolet light 9 using a vacuumsuction force or an electrostatic force. For example, if the mold chuck11 holds the mold 8 using a vacuum suction force, the mold chuck 11 isconnected to an externally installed vacuum pump (not shown), andattachment/detachment of the mold 8 is switched by turning the vacuumpump ON/OFF. Also, each of the mold chuck 11 and the mold drivemechanism 12 has an aperture region 13 at the central portion (theinside thereof) such that the ultraviolet light 9 emitted from the lightirradiation unit 2 is irradiated toward the wafer 10. A lighttransmission member (e.g., a glass plate) is installed within theaperture region 13 such that a space enclosed by a portion of theaperture region 13 and the mold 8 is sealed, and the pressure in thespace is adjusted by a pressure adjusting device (not shown) including avacuum pump, or the like. The pressure adjusting device sets thepressure in the space higher than the external pressure when the mold 8is pressed against a resin 14 on the wafer 10, so that a pattern region8 a is deflected into a convex shape toward the wafer 10 and the patternregion 8 a is brought into contact with the resin 14 from the centralportion of the pattern region 8 a. With this arrangement, gas (air) isprevented from being entrapped between the pattern region 8 a and theresin 14, so that the resin 14 can be filled in every corner of theconvex and concave portion of the pattern region 8 a.

The mold drive mechanism 12 moves the mold 8 in each axis direction soas to selectively press the mold 8 against the resin 14 on the wafer 10,or to release the mold 8 from the resin 14. Examples of an actuatoremployable for the mold drive mechanism 12 include a linear motor, anair cylinder, and the like. Also, the mold drive mechanism 12 may beconstituted by a plurality of drive systems, such as a coarse movementdrive system, a fine movement drive system, and the like, in order toaccommodate positioning of the mold 8 with high accuracy. Furthermore,the mold drive mechanism 12 may have a position adjustment function foradjusting the position of the mold 8, not only in the Z-axis direction,but also, in the X-axis direction, the Y-axis direction, or the θ(rotation about the Z axis) direction, a tilt function for correctingthe tilt of the mold 8, and the like. The pressing operation and thereleasing operation performed by the imprint apparatus 1 may be realizedby moving the mold 8 in the Z-axis direction, may be realized by movingthe wafer stage 4 in the Z-axis direction, or may also be realized bymoving both the mold 8 and the wafer stage 4 relative to each other.

The wafer 10 is, for example, a single crystal silicon substrate or anSOI (Silicon on Insulator) substrate, and an ultraviolet curable resin,i.e., the resin 14, which is molded by the pattern region 8 a formed onthe mold 8, is applied on the treatment surface of the wafer 10.

The wafer stage 4 holds the wafer 10 and executes position matchingbetween the mold 8 and the resin 14 when the mold 8 is pressed againstthe resin 14 on the wafer 10. The wafer stage 4 has a wafer chuck 16that holds the wafer 10 by a suction force and a stage drive mechanism17 that holds the wafer chuck 16 by a mechanical unit and is movable ineach axis direction. Examples of an actuator employable for the stagedrive mechanism 17 include a linear motor, a planar motor, and the like.The stage drive mechanism 17 may also be constituted by a plurality ofdrive systems, such as a coarse movement drive system, a fine movementdrive system, and the like, in the X-axis and Y-axis directions.Furthermore, the stage drive mechanism 17 may also have a drive systemfor adjusting the position of the wafer 10 in the Z-axis direction, aposition adjustment function for adjusting the position of the wafer 10in the θ direction, a tilt function for correcting the tilt of the wafer10, and the like. Also, the wafer stage 4 includes a plurality ofreference mirrors 18 corresponding to the X-, Y-, Z-, ωx-, ωy-, andωz-directions on the side surfaces thereof. In contrast, the imprintapparatus 1 includes a plurality of laser interferometers(length-measuring devices) 19 that measures the position of the waferstage 4 by irradiating these reference mirrors 18 with a beam. The laserinterferometer 19 measures the position of the wafer stage 4 in realtime, and the control unit 7 to be described below executes positioningcontrol of the wafer 10 (the wafer stage 4) based on the measurementvalue.

The application unit 5 is installed near the mold holding mechanism 3and applies the resin (uncured resin) 14 to the wafer 10. Here, theresin 14 is a photocurable resin (imprint material) having the propertyof being cured by being irradiated with the ultraviolet light 9, and isappropriately selected depending on various conditions, such as themanufacturing process of semiconductor devices, or the like. The amountof the resin 14 to be ejected from the ejection nozzle 5 a of theapplication unit 5 is also appropriately determined by a desiredthickness of the resin 14 to be formed on the wafer 10, the density ofthe pattern to be formed, or the like.

The wafer heating mechanism (substrate heating mechanism) 6 is capableof heating only a partial region of the wafer 10. Also, a pattern region(substrate-side pattern region) 20 serving as a portion to be treated,which pre-exists on the wafer 10 carried into the imprint apparatus 1,is heated, to thereby deform the pattern region 20 into a desired shapeor a desired size. FIG. 2 is a schematic diagram illustrating theconfiguration and arrangement of the wafer heating mechanism 6 providedin the imprint apparatus 1, with respect to the mold 8 and the wafer 10.In FIG. 2, the same elements as those in the imprint apparatus 1 shownin FIG. 1 are designated by the same reference numerals, and theexplanation thereof will be omitted. The wafer heating mechanism 6includes a heating light source 22 that irradiates the pattern region 20on the wafer 10 with irradiation light 21 for heating, an opticaladjustor 23 that adjusts the irradiation dose of the irradiation light21, and a reflection plate 25 that defines the optical path, such thatadjusted light 24 is directed toward the surface of the wafer 10. First,it is preferable that the heating light source 22 emits light having awavelength at which the resin 14 serving as an ultraviolet curable resinis not exposed (cured), such as light in a wavelength band of from 400nm to 2000 nm. In particular, from the viewpoint of heating efficiency,light in a wavelength band of from 500 nm to 800 nm is more preferred.Furthermore, the heating light source 22 may also emit, not only lightin the specified wavelength band, but also, ultraviolet light in awavelength band to which the resin 14 is not very sensitive, where thewavelength band is selected from 200 nm to 400 nm at which the resin 14is exposed, as the irradiation light 21. The optical adjustor 23 iscapable of emitting only the irradiation light 21 having a specifiedwavelength toward the surface of the wafer 10 in order to form a desiredirradiation dose distribution on at least the planar region of thepattern region 20. Examples of the optical adjustor 23 may include aliquid crystal device that is capable of changing an irradiation dosedistribution by arranging a plurality of liquid crystal elements on alight-transmitting surface and individually controlling voltages to beapplied to a plurality of liquid crystal elements, or a digital mirrordevice (digital micro mirror device) that is capable of changing anirradiation dose distribution by arranging a plurality of mirrorelements on a light-reflecting surface and individually adjusting thesurface directions of the mirror elements.

It is preferable that the heating light source 22 and the opticaladjustor 23 are provided in the imprint apparatus 1, such that theoptical path of the ultraviolet light 9 emitted from the lightirradiation unit 2 is not disturbed when the resin 14 is cured.Accordingly, in the present embodiment, the heating light source 22 andthe optical adjustor 23 are provided on one side of the upper surface(the light irradiation unit 2 side) of the aperture region 13, which islocated on the ultraviolet light irradiation side of the mold 8, so asto emit the adjusted light 24 therefrom in the X-axis direction. In thiscase, the adjusted light 24 enters into a space connected to theaperture region 13, and then is reflected by the reflection plate 25.The reflected adjusted light 24 is transmitted through the mold 8 tothereby be irradiated onto the pattern region 20 that is present on thewafer 10. On the other hand, the ultraviolet light 9 emitted from thelight irradiation unit 2 is transmitted through the reflection plate 25to thereby be directly irradiated onto the wafer 10.

The control unit 7 may control the operation, adjustment, and the like,of the components of the imprint apparatus 1. The control unit 7 isconstituted by a computer, or the like, and is connected to thecomponents of the imprint apparatus 1 through a line so as to executecontrol of the components by a program, or the like. The control unit 7of the present embodiment controls at least the operation of the waferheating mechanism 6. Note that the control unit 7 may be integrated withthe rest of the imprint apparatus 1 (provided in a shared housing) ormay be provided separately from the rest of the imprint apparatus 1(provided in a separate housing).

Also, the imprint apparatus 1 includes an alignment measurement system(detection unit) 26 that measures the shape or size of the patternregion 20, which is present on the wafer 10, and serves as a part to betreated, during imprint processing.

Here, a plurality of marks (not shown) is formed on the mold 8 and thewafer 10, and the alignment measurement system 26 measures the shape ofthe pattern region 20 by detecting these marks. In one embodiment of thepresent invention, four marks are formed on the mold 8 and the wafer 10,respectively, and the number of marks may be four or more. As shown inFIG. 2, the alignment measurement system 26 may also be able to measureboth of the shape of the pattern region 8 a formed on the mold 8 and theshape of the pattern region 20 formed on the wafer 10 during imprintprocessing.

Furthermore, the imprint apparatus 1 includes a base surface plate 27 onwhich the wafer stage 4 is placed, a bridge surface plate 28 that fixesthe mold holding mechanism 3, and a column 30 that extends from the basesurface plate 27 and supports the bridge surface plate 28 via avibration isolator 29. The vibration isolator 29 eliminates vibrationtransmitted to the bridge surface plate 28 from the floor. Furthermore,the imprint apparatus 1 may also include a mold conveyance mechanism(not shown) that conveys the mold 8 from the exterior of the imprintapparatus 1 to the mold holding mechanism 3 and a substrate conveyancemechanism (not shown) that conveys the wafer 10 from the exterior of theimprint apparatus 1 to the wafer stage 4.

Next, a description will be given of imprint processing performed by theimprint apparatus 1. First, the control unit 7 causes a substrateconveyance mechanism to convey the wafer 10, and to place and to attachthe wafer 10 to the wafer chuck 16 on the wafer stage 4. Next, thecontrol unit 7 drives the stage drive mechanism 17 and causes it to movethe pattern region 20, which is present on the wafer 10 as apattern-forming region (a part to be treated), to the applicationposition of the application unit 5. Next, as an application step, thecontrol unit 7 causes the application unit 5 to apply the resin 14 tothe pattern region 20. Next, the control unit 7 drives the stage drivemechanism 17 again and causes it to move the pattern region 20 such thatthe pattern region 20 on the wafer 10 is placed in a position directlybelow the pattern region 8 a formed on the mold 8. Next, as amold-pressing step, the control unit 7 drives the mold drive mechanism12 so as to press the mold 8 against the resin 14 on the wafer 10. Bypressing the mold 8 against the resin 14, the resin 14 is filled in theconvex and concave portion of the pattern region 8 a. Under thiscondition, as a curing step, the control unit 7 causes the lightirradiation device 2 to emit the ultraviolet light 9 from the topsurface of the mold 8, and cures the resin 14 by the ultraviolet light 9that has been transmitted through the mold 8. Then, after the resin 14is cured, the control unit 7 drives the mold drive mechanism 12 again torelease the mold 8 from the resin 14 as a mold-releasing step. By theaforementioned steps, a three dimensionally shaped pattern (layer) ofthe resin 14 following the convex and concave portion of the patternregion 8 a is formed on the surface of the pattern region 20 on thewafer 10. Such a sequence of imprint operations is conducted two or moretimes while changing the pattern-forming region under the drive of thewafer stage 4, to thereby be able to form a plurality of patterns of theresin 14 on one wafer 10.

Here, in a series of device manufacturing steps, the wafer 10 to besubjected to imprint processing is heated in a film formation step, suchas sputtering, and then is conveyed into the imprint apparatus 1. Thus,the wafer 10 may be expanded or reduced before the wafer 10 is conveyedinto the imprint apparatus 1, resulting in a change in the shape (orsize) of the pattern region 20 in the direction of two orthogonalin-plane axes X and Y. The deformation component of the pattern region20 is mainly classified into a magnification component, a parallelogramcomponent, a trapezoidal component, or a combination thereof.Accordingly, when the mold 8 is pressed against the resin 14 on thewafer 10, the imprint apparatus 1 needs to correct the shape of thepattern region 20 pre-formed on the wafer 10 so as to make the shape ofthe pattern region 20 match the shape of the pattern region 8 a formedon the mold 8. In particular, in the imprint apparatus 1 of the presentembodiment, the control unit 7 calculates the correction amount of theshape of the pattern region 8 a based on the measurement result obtainedby the alignment measurement system 26 to thereby correct the shape ofthe pattern region 20 by thermal deformation.

A general description will now be given of the flow of shape correctionof the pattern region 20. In order to correct the shape of the patternregion 20, i.e., a deformation component, the imprint apparatus 1 formsa temperature distribution for obtaining a desired correction amount atthe inside and the outside of the planar region of the pattern region20. FIG. 3 is a flowchart illustrating the flow of shape correction ofthe pattern region 20 according to the present embodiment. The controlunit 7 causes the alignment measurement system 26 to measure the shapeof the pattern region 20, which is present on the wafer 10 (step S100).Next, the control unit 7 analyzes the deformation component included inthe pattern region 20 based on the measurement result in step S100, andcalculates the correction amount in this case (step S101). Next, thecontrol unit 7 collates the correction amount obtained in step S101 anda previously prepared relational table of the irradiation dosecorresponding to the correction amount for each deformation componentpre- prepared by the heating light source 22 and the optical adjustor 23to thereby derive the irradiation dose required for correcting the shapeof the pattern region 20 (step S102). Then, the control unit 7 controlsthe operation of the heating light source 22 and the optical adjustor 23using the irradiation dose obtained in step S102 as an index (stepS103). At this time, an irradiation dose distribution is formed at theinside and the outside of the planar region of the pattern region 20 inresponse to light (the adjusted light 24) where the irradiation dosethereof is adjusted.

Here, as an example, a specific description will be given of a case whenthe deformation component of the pattern region 20 only includes atrapezoidal component. FIG. 4 is a schematic diagram illustrating thedistribution of irradiation dose corresponding to the shape of thepattern region 20 prior to correction and after correction, and thedistribution of temperature and deformation amount of the pattern region20 in accordance with the irradiation dose. It is assumed that thepattern region 20 includes a trapezoidal component only in the Y-axisdirection (Y-coordinate), and the pattern region 20 is not particularlydeformed in the X-axis direction. First, in step S101, the control unit7 recognizes that the deformation component of the pattern region 20 isa trapezoidal component, in which the upper base of the pattern region20 in the positive Y-axis direction is narrower than the lower basethereof, having a normal width as shown in the leftmost one in FIG. 4,and simultaneously calculates a correction amount, i.e., an amountrequired for returning the width of the upper base back to normal. Next,in step S102, the control unit 7 collates the correction amount obtainedin step S101 and the relational table to thereby derive the requiredirradiation dose. Then, the control unit 7 causes the heating lightsource 22 and the optical adjustor 23 to operate to form an irradiationdose distribution 40 for the pattern region 20 only in the Y-axisdirection. At this time, since the correction width is maximized at theupper base thereof and gradually decreases from the upper base to thelower base thereof, the irradiation dose distribution 40 is linear, asshown in FIG. 4. Since it is assumed that there is no trapezoidalcomponent deformation of the pattern region 20 in the X-axis direction,the irradiation dose in the X-axis direction is uniform. In this manner,the pattern region 20 is irradiated with the adjusted light 24 where theirradiation dose distribution 40 is adjusted, and thus, is heated with atemperature distribution 41, as shown in FIG. 4. Here, the reason whythe temperature distribution 41 does not uniformly rise from the lowerbase to the upper base of the pattern region 20, but falls in thevicinity of the upper base thereof, is that heating is not performed ina region on the outside of the pattern region 20, resulting in areduction of the temperature of the outer periphery of the patternregion 20 by heat radiation. Although a portion at both ends of theupper base of the pattern region 20 remains deformed, as shown in therightmost one in FIG. 4, the pattern region 20 is heat-deformed inaccordance with a deformation amount distribution 42, as shown in FIG.4, and is corrected to a shape approximating a desired shape. Here,although the pattern region 20 is also heat-deformed in the Y directionby the input of heat into the wafer 10, a detailed description will begiven of deformation mainly in the X direction. A mold shape correctionmechanism 201 to be described below may correct the thermal deformationof the pattern region 20 in the Y direction.

Furthermore, in comparison with the example shown in FIG. 4, there isalso another method for further improving superposition accuracy bybringing the shape of the pattern region 20 after correction furtherinto approximation with a desired shape. FIG. 5 is a schematic diagramillustrating another example of shape correction of the pattern region20 corresponding to that shown in FIG. 4. In the example shown in FIG.5, the heating zone of the pattern region 20 is not limited to theplanar region of the pattern region 20, but includes a region 50positioned above the upper base of the pattern region 20. In the exampleshown in FIG. 4, because heating is not performed in the outer regionpositioned above the upper base of the pattern region 20, a portion inwhich the temperature falls in the temperature distribution 41 and thedeformation amount decreases in the deformation amount distribution 42occurs at the planar region of the pattern region 20. In contrast, inthe example shown in FIG. 5, the region 50 is also included as a heatingzone. Thus, a temperature distribution 52 and a deformation amountdistribution 53 are linear with respect to an irradiation dosedistribution 51, as shown in FIG. 5, at the planar region of the patternregion 20, and a portion in which the temperature falls in thetemperature distribution 52 and the deformation amount decreases in thedeformation amount distribution 53 does not occur at the planar regionof the pattern region 20. Thus, the pattern region 20 is substantiallycorrected to a desired shape as shown in the rightmost one in FIG. 5.

For the correction of the shape of the pattern region 20 as describedabove, the irradiation dose of the adjusted light 24 is temporallyconstant, and thus, a displacement amount 60 with respect to a heatingtime of the pattern region 20 changes at the start of heating, butbecomes stable after the elapse of a predetermined time, as shown inFIG. 6. Thus, when the displacement amount 60 of the pattern region 20becomes stable, the control unit 7 aligns the shape of the patternregion 20 and the shape of the pattern region 8 a formed on the mold 8,and proceeds to the mold-pressing step. In this manner, the imprintapparatus 1 corrects the shape of the pattern region 20, and then formsthe pattern of the resin 14 on the planar region of the pattern region20. Consequently, the shape of the pattern region 20 can be matched withthe shape of the pattern region 8 a with high accuracy. Here, in theconventional imprint apparatus, the mold holding mechanism 3 may havethe mold shape correction mechanism 201 (magnification correctionmechanism) that corrects the shape of the mold 8 (the pattern region 8a) by imparting an external force or displacement to the sides of themold 8. In the imprint apparatus 1 of the present embodiment, the shapeof the pattern region 20 can be matched with the shape of the patternregion 8 a with high accuracy, as compared with the case when thetrapezoidal component is corrected by deforming only the mold 8 usingthe conventional shape correction mechanism. In this manner, the patternformed in the pattern region 20 and the newly-formed pattern of theresin 14 can be superposed with each other with high accuracy.

Next, in the present embodiment, a description will be given of theimprint processing including a step of deforming the shape of the mold 8using the mold shape correction mechanism 201.

FIG. 7 is a flowchart illustrating the imprint processing that includesa step of deforming the shape of the mold 8. First, the control unit 7causes the substrate conveyance mechanism to convey the wafer 10 towhich the resin 14 is applied under the mold 8 (step S300). Next, thecontrol unit 7 causes the alignment measurement system 26 to measure theshape of the pattern region 8 a formed on the mold 8 and the shape ofthe pattern region 20 formed on the wafer 10 (step S301). Next, thecontrol unit 7 analyzes a deformation component included in the patternregion 20 based on the measurement result (information) obtained in stepS301 (step S302). Here, the deformation component is a differencebetween the shapes of the pattern region 8 a formed on the mold 8 andthe pattern region 20 formed on the wafer 10. Next, the control unit 7calculates the correction amount of the pattern region 8 a to be made bythe mold shape correction mechanism 201, the irradiation dosedistribution, and the irradiation dose of the substrate heating lightsource 22, so that the difference in shapes therebetween are reduced,based on the result of analysis in step S302 (step S303). Next, thecontrol unit 7 causes the mold shape correction mechanism 201 to correctthe shape of the pattern region 8 a based on the correction amountcalculated in step S303 (force applying step: step S304). The controlunit 7 also causes the alignment measurement system 26 to measure theshapes of the pattern region 8 a and the pattern region 20 during thecorrection of the pattern region 8 a, and always reflects the obtainedmeasurement result on the correction amount to be made by the mold shapecorrection mechanism 201. After step S304, or concurrently with stepS304, the control unit 7 causes a space optical modulator 23 to heat thewafer 10 based on the irradiation dose distribution calculated in stepS303 to thereby correct the shape of the pattern region 20 formed on thewafer 10 (step S305). The control unit 7 causes the alignmentmeasurement system 26 to measure the shapes of the pattern region 8 aformed on the mold 8 and the pattern region 20 on the wafer 10 duringthe correction of the pattern region 20, and always reflects theobtained measurement result on the irradiation dose distribution to beprovided by the space optical modulator 23.

After the correction of the shape of the pattern region 8 a and theshape of the pattern region 20 formed on the wafer 10, a mold-pressingoperation, during which the mold 8 is brought into contact with thewafer 10 via the resin 14 so that the resin 14 is filled in the concaveand convex pattern of the pattern region 8 a, is started (step S306).After the completion of the mold-pressing operation, as in step S301,the control unit 7 causes the alignment measurement system 26 to measurethe shapes of the pattern region 8 a formed on the mold 8 and a patternregion 51 formed on the wafer 10 again, and performs the operation insteps S303 and S304 again, based on the obtained remeasurement result.

Next, an exposure operation is started when ultraviolet light is emittedfrom the light irradiation unit 2 in order to cure the resin 14 withlight (step S307). After the completion of the exposure operation, amold-releasing operation is started to release the mold 8 from the wafer10 (step S308). After the completion of the mold-releasing operation,the control unit 7 moves the wafer stage 4 in order to apply the resin14 to the target position of the next shot (step S309). Heating thewafer 10 in step S305 is continued until the completion of themold-pressing operation in step S306 and the completion of the exposureoperation in step S307. Furthermore, heating the wafer 10 in step S305may be continued until the completion of the mold-releasing operation instep S308.

The control unit 7 causes the alignment measurement system 26 to alwaysmeasure the shapes of the pattern region 8 a formed on the mold 8 andthe pattern region 20 formed on the wafer 10 during the correction ofthe shapes of the pattern region 8 a and the pattern region 20 formed onthe wafer 10. However, in order to increase the throughput of theapparatus, the alignment measurement system 26 may measure the shapes ofthe pattern region 8 a formed on the mold 8 and the pattern region 20formed on the wafer 10 before all of the patterns 20 formed on the wafer10 are subject to imprint processing. The control unit 7 calculates thecorrection amount of the pattern region 8 a to be made by the mold shapecorrection mechanism 201 and the irradiation dose distribution of thespace optical modulator 23, in advance, based on the obtainedmeasurement result. In this manner, the control unit 7 can cause thealignment measurement system 26 not to measure the shapes of the patternregion 8 a formed on the mold 8 and the pattern region 20 formed on thewafer 10 during imprint processing (steps S301 to S308).

Furthermore, in the present embodiment, the control unit 7 causes themold shape correction mechanism 201 to correct the shape of the patternregion 8 a (step S304) and the space optical modulator 23 to correct theshape of the pattern region 20 (step S305) prior to the start of themold-pressing operation in step S306. Such processing is useful when theresin 14 has a particularly high viscosity, and it is contemplated thatthe correction amount is decreased after the pattern region 8 a isbrought into contact with the pattern region 20 on the substrate 10 viathe resin 14.

For the correction of the shape of the pattern region 20, a descriptionhas been given of the correction for the trapezoidal component. Forexample, when the magnification component is corrected, the control unit7 may control the optical adjustor 23, such that a uniform temperaturedistribution is formed at the inside and the outside of the planarregion of the pattern region 20. Likewise, when the deformationcomponent, such as a barrel deformation component or a pincushiondeformation component is corrected, the control unit 7 may control theoptical adjustor 23, such that an appropriate temperature distributionis formed in the planar region of the pattern region 20. Furthermore,for the correction of the shape of the pattern region 20, theirradiation dose distribution is formed only in the Y-axis direction ofthe pattern region 20. However, the irradiation dose distribution may beformed in the X-axis direction of the pattern region 20 depending on thedeformation component or the irradiation dose distribution may be formedin the X-axis and Y-axis directions of the pattern region 20.

As described above, according to the present embodiment, the imprintapparatus 1, that is advantageous for superposition of the patternformed in the pattern region 20 pre-existing on the wafer 10 and thepattern of the resin 14 to be newly formed during imprint processing,may be provided.

Second Embodiment

Next, a description will be given of an imprint apparatus according to asecond embodiment of the present invention. A feature of the imprintapparatus of the present embodiment lies in the fact that an irradiationmethod for irradiating the adjusted light 24 used for the correction ofthe shape of the pattern region 20 according to the first embodiment ischanged in order to improve throughput. In the imprint apparatus 1 ofthe first embodiment, the irradiation dose of the adjusted light 24 isconstant over time. Thus, as shown in FIG. 6, a predetermined amount oftime is required until the displacement amount 60 is stabilized.Accordingly, in the present embodiment, in order to bring thedisplacement amount of the pattern region 20 closer to a constant valuefaster than the displacement amount 60 of the pattern region 20 of thefirst embodiment, the pattern region 20 is irradiated with the adjustedlight 24 in a stepwise manner during the correction of the shape of thepattern region 20.

FIGS. 8A to 8C show a graph plotting the irradiation dose of theadjusted light 24 and the displacement amount obtained in this case withrespect to the heating time during the correction of the shape of thepattern region 20 according to the present embodiment. In particular,FIG. 8A is a graph showing the relation between the irradiation doseirradiated in a stepwise manner and the heating time. In this case, thecontrol unit 7 controls the irradiation dose of the adjusted light 24such that the irradiation dose is greater than that of the firstembodiment from the start of irradiation with the adjusted light 24until the elapse of a time A, but the irradiation dose is less than thatof the first embodiment after the elapse of the time A. Here, the time Ais shorter than a time B (see FIG. 8B, to be described below) requiredfor the displacement amount 60 of the first embodiment to be stabilized,but is preferably less than half the time B. FIG. 8B is graph showingthe relation between the displacement amount corresponding to theirradiation dose shown in FIG. 8A and the heating time. In this case,the displacement amount 61 of the pattern region 20 rises in a shorttime in comparison with the displacement amount 60 of the firstembodiment and the irradiation dose is optimally decreased at the timeA, so that the displacement amount 61 can be stabilized in a short time.The profile of the irradiation dose of the present embodiment is notlimited to a continuous profile, as shown in FIG. 8A. For example, asshown in FIG. 8C, the profile of the irradiation dose may also be anintermittent profile, such that the irradiation dose is temporarily setto zero at the time A, and a constant irradiation dose is given againafter the elapse of a predetermined time.

Other Embodiments

Next, as other embodiments of the present invention, a description willbe given of various other examples of the imprint apparatus of theembodiments. First, in the aforementioned embodiments, the wafer heatingmechanism 6 employs the optical adjustor 23 during the correction of theshape of the pattern region 20 that is present on the wafer 10, but thepresent invention is not limited thereto. For example, instead of theoptical adjustor 23, a plurality of heating light sources 70 that emitsheating light toward the planar region of the pattern region 20 from agap between the mold 8 and the wafer 10, as shown in FIG. 9, may also beemployed. In this case, the control unit 7 appropriately adjusts theposition of light that is projected onto the surface of the patternregion 20 or the heating area of the outer peripheral region thereofusing a plurality of heating light sources 70 to thereby form theirradiation dose distribution and the temperature distribution onto thepattern region 20. This eliminates the need to ensure the optical pathof the adjusted light 24 by disposing the reflection plate 25 in theaperture region 13, and thus, a plurality of heating light sources 70may be readily provided in a typical imprint apparatus. Instead ofemploying a plurality of heating light sources 70, the wafer heatingmechanism 6 may also be configured such that a heater is provided on thewafer chuck 16 so as to deform the pattern region 20 by heating with theheater. In this case, it is preferable that the heater be divided into aplurality of regions so as to form a temperature distribution in thewafer 10, and the plurality of regions are individually controlled bythe control unit 7.

Furthermore, while, in the embodiment, the correction of the shape ofthe pattern region 20 is performed in a state in which the mold 8 is notin contact with the resin 14 on the wafer 10, the pattern region 20 maybe continuously irradiated with the adjusted light 24, even when themold 8 is in contact with the resin 14 during the mold-pressing step, inorder to maintain the displacement amount 60 of the pattern region 20.Also, the correction of the shape of the pattern region 20 may beperformed in parallel with the mold-pressing step or the curing step.For example, when the mold 8 is brought into contact with the wafer 10via the resin 14 during the mold-pressing step, the heat of the patternregion 20 may be transferred to the mold 8. In this case, thedeformation amount of the pattern region 20 changes due to a reductionin the temperature thereof depending on the heat capacity of the mold 8,resulting in adverse effects on superposition accuracy. In contrast, inthe imprint apparatus 1 of the present embodiment, a reduction in thetemperature of the pattern region 20 can be suppressed by performing themold-pressing operation (step S306) prior to the irradiation of thewafer 10 with the adjusted light 24 (step S306) in the steps shown inFIG. 7 described in the first embodiment. When heating is performed formaintaining the shape of the pattern region 20 after the correctionthereof, the value of the irradiation dose on the pattern region 20 maybe less than that during the correction of the shape of the patternregion 20.

In the present embodiment, the correction of the shape of the patternregion 8 a is performed by the mold shape correction mechanism 201 (stepS304), and then, the mold-pressing operation is performed (step S306).However, the present invention is not limited thereto, and the shape ofthe pattern region 8 a (step S304) and the shape of the pattern region20 formed on the wafer 10 (step S305) may be corrected after themold-pressing operation (step S306).

In the present embodiment, the correction amount of the pattern region 8a and the correction amount of the pattern region 20 formed on the wafer10 are calculated, in step S303. However, the present invention is notlimited thereto, and the correction amount of the pattern region 20formed on the wafer 10 in step S303 may be calculated after the patternregion 8 a is corrected, in step S304.

(Article Manufacturing Method)

A method of manufacturing a device (e.g., a semiconductor integratedcircuit element, a liquid display element, or the like) as an articlemay include a step of forming a pattern on a substrate (a wafer, a glassplate, a film-like substrate, or the like) using the imprint apparatusdescribed above. Furthermore, the manufacturing method may include astep of etching the substrate on which a pattern has been formed. Whenother articles, such as a patterned medium (storage medium), an opticalelement, or the like, are manufactured, the manufacturing method mayinclude another step of processing the substrate on which a pattern hasbeen formed, instead of the etching step. The article manufacturingmethod of the present embodiment has an advantage, as compared with aconventional article manufacturing method, in at least one ofperformance, quality, productivity, and production cost of an article.

While the embodiments of the present invention have been described withreference to exemplary embodiments, it is to be understood that theinvention is not limited to the disclosed exemplary embodiments. Thescope of the following claims is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures and functions.

We claim:
 1. An imprint apparatus that forms a pattern of an imprintmaterial on a substrate-side pattern region of a substrate by using amold, the imprint apparatus comprising: a heating unit configured toheat a partial region of the substrate, the partial region correspondingto the substrate-side pattern region, by irradiating the substrate withlight that has passed through the mold and has a first wavelengthdifferent from light having a second wavelength that is used for curingthe imprint material, wherein the heating unit is configured to heat thepartial region to deform the substrate-side pattern region by forming anuneven temperature distribution on the substrate-side pattern region byirradiation of the light having the first wavelength with an unevenillumination distribution.
 2. The imprint apparatus according to claim1, wherein the heating unit heats the partial region by irradiation ofthe light having the first wavelength, even while the imprint materialis irradiated with the light having the second wavelength.
 3. Theimprint apparatus according to claim 1, wherein the heating unitincludes an optical adjuster configured to adjust the illuminationdistribution of the light having the first wavelength.
 4. The imprintapparatus according to claim 3, wherein the optical adjuster is one of(i) a liquid crystal device in which a plurality of liquid crystalelements are arranged and (ii) a digital mirror device in which aplurality of mirror elements are arranged.
 5. The imprint apparatusaccording to claim 1, wherein the heating unit heats the partial regionbased on a difference between a shape of a mold-side pattern region ofthe mold and a shape of the substrate-side pattern region.
 6. Theimprint apparatus according to claim 1, wherein the heating unit heatsthe partial region such that a shape difference between a shape of amold-side pattern region of the mold and a shape of the substrate-sidepattern region are reduced.
 7. The imprint apparatus according to claim1, wherein the heating unit heats the partial region to adjust a shapeof the substrate-side pattern region.
 8. The imprint apparatus accordingto claim 1, wherein the partial region includes the substrate-sidepattern region and an outside region other than the substrate-sidepattern region, the outside region being next to the substrate-sidepattern region.
 9. The imprint apparatus according to claim 1, whereinthe first wavelength is from 400 nm to 800 nm.
 10. An imprint method forforming a pattern of an imprint material on a substrate-side patternregion of a substrate by using a mold, the method comprising: deforminga partial region of the substrate, the partial region corresponding tothe substrate-side pattern region, by irradiating the substrate withlight that has passed through the mold and has a first wavelengthdifferent from light having a second wavelength that is used for curingthe imprint material; and curing the imprint material by irradiating thelight having the second wavelength in a state in which thesubstrate-side pattern region is deformed and the mold is contacted withthe imprint material, wherein the step of deforming includes forming anuneven temperature distribution on the substrate-side pattern region byirradiation of the light having the first wavelength with an unevenillumination distribution.
 11. A device manufacturing method formanufacturing a device, the method comprising: (a) forming a pattern ofan imprint material on a substrate-side pattern region of a substrate byusing a mold under an imprint method; and (b) processing the substrateon which an imprint material pattern has been formed to manufacture thedevice, wherein the imprint method comprises: (i) deforming a partialregion of the substrate, the partial region corresponding to thesubstrate-side pattern region, by irradiating the substrate with lightthat has passed through the mold and has a first wavelength differentfrom light having a second wavelength that is used for curing theimprint material; and (ii) curing the imprint material by irradiatingthe light having the second wavelength in a state in which thesubstrate-side pattern region is deformed and the mold is contacted withthe imprint material, wherein the step of deforming includes forming anuneven temperature distribution on the substrate-side pattern region byirradiation of the light having the first wavelength with an unevenillumination distribution.
 12. An imprint method for forming a patternof an imprint material on a substrate-side pattern region of a substrateby using a mold, the method comprising steps of: obtaining shapedifference information between a mold-side pattern region of the moldand the substrate-side pattern region; deforming the mold-side patternregion by applying a force to the mold and the substrate-side patternregion by irradiating a partial region of the substrate, the partialregion corresponding to the substrate-side pattern region, with lightthat has passed through the mold and has a first wavelength; and curingthe imprint material in a state in which the imprint material on thedeformed substrate-side pattern region is brought into contact with themold by irradiating light having a second wavelength different from thefirst wavelength, wherein, in the step of deforming, the force and anilluminance distribution of the light are controlled based on theobtained shape difference.
 13. The imprint method according to claim 12,wherein, in the step of obtaining, the shape difference is obtained bydetecting a plurality of marks formed on the mold and a plurality ofmarks formed on the substrate.
 14. The imprint method according to claim13, wherein, in the step of obtaining, both a number of the plurality ofmarks formed on the mold and a number of the plurality of marks formedon the substrate are at least four, each of the plurality of marks onthe mold being disposed at a corner of the mold-side pattern, and eachof the plurality of marks on the substrate being disposed at a corner ofthe substrate-side pattern.
 15. The imprint method according to claim12, wherein, in the step of deforming, the partial region is irradiatedwith light having an uneven illuminance distribution, to generate anuneven temperature distribution within the partial region.
 16. Theimprint method according to claim 12, wherein, in the step of deforming,the partial region is irradiated to generate a temperature distributionin the substrate-side pattern region by heating the substrate-sidepattern region and an outside region, which is outside of thesubstrate-side pattern region and next to the substrate-side patternregion.
 17. The imprint method according to claim 12, wherein, in thestep of deforming, the substrate is irradiated with light having a firstirradiation dose per unit time that is lower than a second irradiationdose per unit time, after the substrate is irradiated with the lighthaving the second irradiation dose.
 18. The imprint method according toclaim 12, wherein, in the step of deforming, the force and theilluminance distribution are controlled based on the obtained shapedifference information, so as to reduce the shape difference.
 19. Theimprint method according to claim 12, wherein an uncured imprintmaterial on the substrate-side pattern region is not cured by receivinglight having the first wavelength.
 20. A device manufacturing method formanufacturing a device, the method comprising: (a) forming a pattern ofan imprint material on a substrate-side pattern region of a substrate byusing a mold under an imprint method; and (b) processing the substrateon which an imprint material pattern has been formed to manufacture thedevice, wherein the imprint method comprises steps of: (i) obtainingshape difference information between a mold-side pattern region of themold and the substrate-side pattern region; (ii) deforming the mold-sidepattern region by applying a force to the mold and the substrate-sidepattern region by irradiating a partial region of the substrate, thepartial region corresponding to the substrate-side pattern region, withlight that has passed through the mold and has a first wavelength; and(iii) curing the imprint material in a state in which the imprintmaterial on the deformed substrate-side pattern region is brought intocontact with the mold by irradiating light having a second wavelengthdifferent from the first wavelength, wherein, in the step of deforming,the force and an illuminance distribution of the light are controlledbased on the obtained shape difference.